The present invention relates to novel imidazoquinolone derivatives having a 1H, 5H-imidazo[4,5-c]quinolin-4-one skeleton and showing broncho-dilatory and antiallergic activities.
1H-imidazo[4,5-c]quinolines useful as a broncho-dilator and 1H-imidazo[4,5-c]quinoline-4-amines useful as an antiviral agent, represented by the following formula are disclosed in Japanese Published Unexamined Patent Application No. 123488/85 [U.S. Pat. Nos. 4698348 and 4689338, and EP-A-145340] ##STR3## wherein R.sup.A represents hydrogen, alkyl, benzyl, phenyl, etc.; R.sup.B represents hydrogen, alkyl, etc.; and R.sup.c represents hydrogen, hydroxyl, alkylamino, etc.